1. Field of the Invention
The present invention relates to an envelope detecting circuit that may generate an envelope signal of an input radio-frequency (RF) signal.
2. Related Background Art
It has been known that an envelope detecting circuit implements an active element such as a field effect transistor (FET) where an FET is operable as a diode. A Japanese Patent Application laid open No. JP-2000-068747A has disclosed such an envelope detecting circuit. However, when a transistor, which is a three-terminal device, is used as a diode, which is a two-terminal device, the transistor used therein shows no function to amplify an input signal, which results in a restricted output power.